Our Meltdown mitigation state isn't exposed outside of cpufeature.c,
contrary to the rest of the Spectre mitigation state. As we are going
to use it in KVM, expose a arm64_get_meltdown_state() helper which
returns the same possible values as arm64_get_spectre_v?_state().
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/spectre.h | 2 ++
arch/arm64/kernel/cpufeature.c | 20 +++++++++++++++++---
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h
index fcdfbce302bd..52e788981f4a 100644
--- a/arch/arm64/include/asm/spectre.h
+++ b/arch/arm64/include/asm/spectre.h
@@ -29,4 +29,6 @@ bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope);
void spectre_v4_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
void spectre_v4_enable_task_mitigation(struct task_struct *tsk);
+enum mitigation_state arm64_get_meltdown_state(void);
+
#endif /* __ASM_SPECTRE_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6f36c4f62f69..280b10762f6b 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2846,14 +2846,28 @@ static int __init enable_mrs_emulation(void)
core_initcall(enable_mrs_emulation);
+enum mitigation_state arm64_get_meltdown_state(void)
+{
+ if (__meltdown_safe)
+ return SPECTRE_UNAFFECTED;
+
+ if (arm64_kernel_unmapped_at_el0())
+ return SPECTRE_MITIGATED;
+
+ return SPECTRE_VULNERABLE;
+}
+
ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
char *buf)
{
- if (__meltdown_safe)
+ switch (arm64_get_meltdown_state()) {
+ case SPECTRE_UNAFFECTED:
return sprintf(buf, "Not affected\n");
- if (arm64_kernel_unmapped_at_el0())
+ case SPECTRE_MITIGATED:
return sprintf(buf, "Mitigation: PTI\n");
- return sprintf(buf, "Vulnerable\n");
+ default:
+ return sprintf(buf, "Vulnerable\n");
+ }
}
--
2.28.0
